首页
登录
职称英语
As every schoolboy knows, insects pollinate flowers, while birds and mammals
As every schoolboy knows, insects pollinate flowers, while birds and mammals
游客
2023-10-16
66
管理
问题
As every schoolboy knows, insects pollinate flowers, while birds and mammals disperse seeds by eating fruits or transporting burs on their feathers and fur. These are examples of co-evolution, a phenomenon first described by Charles Darwin in The Descent of Man, and Selection in Relation to Sex, published in 1871.
Co-evolution, in which two species have evolved together in response to adaptations that each has imposed on the other, can be extremely subtle. For instance, some animals may help to transfer pollen from one plant to another without acting directly as the carrier themselves. Instead, they make it easier for the pollen to be dispersed by other creatures. Mats Olsson and Richard Shine, of the University of Sydney, and Elisabeth Bak-Olsson, of the University of Gothenburg in Sweden, have discovered, apparently for the first time, such a mutually beneficial arrangement between a reptile and a plant.
For most of the year the Tasmanian snow skink lizard confined to mountain tops in that island is catholic in what it eats. But when the honey-bush is in bloom, the skinks make a point of tearing off the tough, red petals that enclose the rest of the flower. They chew them to extract the nectar and spit out what is left. At first sight, this skink-savaging may not seem all that helpful to the honey- bush. But it is. It exposes the reproductive parts of the flowers, thereby allowing pollinating insects to get at them. Dr. Olsson and his colleagues found that flowers with the petals left intact never produced seed. But, according to their paper in the Biological Journal of the Linnean Society, 87% of flowers with the petals torn off did so.
To check that it was the skinks alone that were the plants’ little helpers, the researchers placed cages around some honey-bushes. Virtually all of the petals were removed from the flowers on bushes without cages. Only 16% of the caged bushes had their petals ripped off, possibly by high winds battering them.
Dr Olsson found no evidence of pollen being carried on a skink and so concluded that the lizards play no role in transporting honey-bush pollen from one flower to another. But he did see a range of insects: wasps, flies, bumble-bees and others feeding from honey-bush flowers that had no petals covering them. Without the petals removed, it was impossible for insects to do any pollinating.
SUMMARY:
Co-evolution is【51】described by Charles Darwin in The Descent of Man. In the process of co-evolution, two species may have to respond to adaptations they have imposed on each other.
For example, some animals may not carry.【52】from one plant to another. They may help by making it easier for other creatures to disperse the pollen from one plant to another. Such an arrangement seems【53】to both species. In Tasmania, the skink lizards chew the red petals of【54】and spit out what is left. In doing so, they expose the reproductive parts of the flower and enable pollinating insects to reach them. It was discovered that 87% of these flowers produced seeds. Conversely, flowers with petals remaining【55】never did. [br]
选项
答案
Pollen
解析
(由some animals may help to…directly as the carrier themselves意为“它们会传递花粉,但是自己却不是直接的传递者”。)
转载请注明原文地址:https://tihaiku.com/zcyy/3102909.html
相关试题推荐
Mygardenhaslargetrees.Mygardenhasflowerswhichsmelllovelywheninbloo
-WhatamIgoingtodoaboutapresentforCarol?-You______someflowers.A、mig
Mygardenhaslargetrees.Mygardenhasflowerswhichsmelllovelywheninbloo
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
随机试题
Weareverymuchimpressedbythehighqualityandcompetitivepriceofyourpro
[originaltext]AsktheaverageAmerican,"Whatisfreedom?"Youwillprobabl
Text3Scientistshavefoundthatalthou
属于伤害一级预防的内容是A.摩托车头盔 B.汽车安全带 C.救生衣 D.交
根据《建设工程质量管理条例》,设计单位的质量责任包括()。
(2016年真题)下列条款不可以嵌入债券的是()。A.延期条款 B.转换
咨询机构为客户提供咨询服务时,评价其采用的方法是否有效的主要标准是()。A.方
用简单随机抽样方法抽取样本,如果要使抽样标准误降低50%,则样本容量需要扩大的倍
某公司正在论证新建一条生产线项目的可行性。经测算,项目的经济寿命为5年,项目固定
根据我国《建筑法》,建设单位应当自领取施工许可证之日起()个月内开工。A.
最新回复
(
0
)